1. Technical Field
The present invention relates to printing systems.
2. Related Art
Printing devices typically print based on data indicating whether or not to form a dot for each pixel (dot data). Dot data is normally generated by converting image data of the RGB format. The greater the resolution of the image, the longer this conversion takes.
Accordingly, a technique is known that reduces the amount of time required for conversion by grouping a plurality of pixels together and carrying out a process based on whether or not an edge is present within the group. The “edge” mentioned here refers to a border line produced as a result of a sudden change in color, brightness, or the like. With this technique, groups that have an edge are converted normally, whereas the information in groups that do not have an edge is compressed, after which the conversion is carried out. This conversion is normally executed by a host device (a computer) that communicates with the printer. The dot data generated through the conversion is transferred from the host device to the printer as data for printing. The printer then prints based on the transferred dot data (for example, see JPA-2004-289274).
The aforementioned past technique attempted to both reduce the amount of time required to transfer data for printing to the printer and suppress a drop in the printing quality. Recently in particular, increases in the speed with which host devices convert dot data, increases in the speed with which line printers transport paper, and so on have resulted in a situation in which the time required for transferring data from a host device to a printer is a determining factor in the printing process. Accordingly, reducing the time of the data transfer has been an issue. Of course, a reduction in the data transfer time can easily be realized by reducing the resolution, but doing so will result in an equivalent drop in image quality. Accordingly, both reducing the amount of time required to transfer data for printing to the printer and suppressing a drop in the printing quality has been an issue.